Method of printing on textile fabrics



f UNITED STATES PATENT. OFFICE.

toms PRANG, or BOSTON, MASSACHUSETTS.

METHOD OF PRINTING ON TEXTILE FABRICS.

SPECIFICATION formingpart of Letters latent No. 224,949, dated February24, 1880.

Application filed December 6, 1879.

that ot'chromographic printing, and it is es" pecially intended tofacilitate the production of colored pictures ordesigns upon wovenmaterials, the elastic and stretching qualities of which give rise todifliculty in maintaining an accurate register.

In United States Patent No.113,343, granted to me. a method is describedfor so treating textile fabrics as to overcome this difficulty.

Tao

The present invention accomplishes the same end more perfectly and bysimpler means, which are at the same time very thoroughly under theworkmans control.

To secure the accurate register of two or more colors printeduponfabrics of silk, cotton, flax, or wool, and to accomplish this insuch a manner that the material, after having received the severalprintings, shall not have suffered in appearance or otherwise, I proceedas follows: A sheet of stiff paper (or other non-extensible material) isto be coveredon one side with a coating of starch or flour paste, glue,or similar adhesive substance, and dried. In my practicel prefer to usecommon starch made into a paste with hot Water for coating the paper.The silk or other material to be printed upon is next damped evenly andthen spread flat in contact with the driedsurface upon the paper, andpressure applied in -a lithographic or other suitable press, or in anyother effective manner. The textile fabric so treated will adhere to thesheet, and the printing can then be proceeded with, as far i as theregistration is concerned, exactly as in the case of printing colorsupon paper alone. It is not necessary for the end in View that the wovenstuif should stick strongly to the paper; on the contrary, all that isrequired is an ad hesiou strong enough to control the elasticity of thefabric and to keep all parts of it in intimate contact with the paperduring the several printings.

The degree of adhesion depends on three circumstances-viz., the natureof the adhesive paste dried upon the paper, the degree of pressureapplied, and, above all, on the amount of moisture in the textilefabric. The first two conditions areeasilymaintainedconstant. The lastcan be varied and graduated with great nicety, (by means well known topractical printers,) and maintained without further change when thedesirable degree of adhesion is secured. The control which the workmancan thus exert is very important, because of its bearing upon the nextoperation-namely, the removal of the fabric uninjured from the paperafter the printing upon it has been completed. This I accomplish bysimply tearing them asunder mechanically.

When, in the manner hereinbefore described,

rial has been properly done, its removal from the paper in this way iseasy and certain. The force required will not be sufficient to drag theadhesion be strong enough to tear off particles of paper or paste on theone hand, or to injure the surface of the textile fabric upon the other.The material will, in fact, be quite unchanged in appearance, except bythe colors printed upon it. v

If the attempt be made to effect the temporary mounting by damping thepasted surface upon the paper, and then applying the fabric, dry ordamp, thereto, it will be unsafe to depend upon mechanical means aloneto finally separate them, because the exact tenacity with which theywill adhere cannot be controlled and determined beforehand. In suchcases a redamping after printing will inevitably be necessary to causethe paste to let go easily and equally. This arises from the fact thatit is impossible to provide an adhesive surface upon the paper whichwill have the same adwhich will be identical in this respect. Uniformityof this kind depends upon the regular and equal thickness of the coatingof adhesive matter and (if it has been dried) upon the time during whichit was exposed to the moistenin g influence. When such damping iseffected in the usual waynamely, by placing the sheet to be dampedbetween sheets of moist paper, the quantity of Water in which has beenthe temporary mounting of the textile mate-' hesiveness everywhere, ortwo distinct sheets the silk or other cloth out of shape, nor willaccurately determined by well-known tentative methods-the dry pastedsurface continues to absorb water gradually until it has acquired a moreor less softened or gelatinous condition throughout its thickness. Whensuch a surface is forcibly brought in contact with that of a textilefabric the softened material is crushed and driven between the fibers,and a very close and firm adhesion at the thickest part of the coatingis sure to follow. After such treatment the only way of separating thetwo is to remoisten the whole and pull them apart; but in so doing,besides the time and trouble it requires, some of the paste or starchalways remains attached to the cloth and changes its character by makingit stiff and harsh.

In my present invention, hereinbefore described, the very slight amountof moisture retained in the fabric at the time it is taken from the pileof damp paper (or otherwise uniformly damped) acts upon the dry coatingof paste only at the instant the pressure is applied. There is not time,under these circumstances, for the penetration and softening of thewhole thickness of the layer of paste, in consequence of whichirregularities in its thickness produce no effect, and there can be nocrushing or absorption of the glutinous substance by the fibrousmaterial. In no other way known to me is it possible to secure evenadhesion on all parts of the same sheet, or on ure to the surface of acoating of dry adhesive matter upon paper, so that it shall adhere tothe same, printi n g successiveimpressions thereon with the usualprecautions for maintaining a register, and then separating the fabricmechanically from its temporary backing, in the manner and for thepurposes described.

2. The improvement in the art of controlling the tenacity of adhesionexisting between two pliant materials pasted together-the one paper, theother a textile fabricwhich consists in applying to the former anadhesive coating,

drying the same, damping the other uniformly with a definite amount ofwater, and then pressing them together, in the manner and for thepurposes described.

' LOUIS PRANG. WVitnesses HERMAN RICHTER, AMANDUS MEYER.

